Archive for the ‘Tips & tricks’ Category

You’ve noticed by now the new download URL’s we started using. There is a reason to this change.

Putting your software or content on some server to download is pretty straightforward. You put it, they download it, end of story. Right? “Honey, let’s take it in house, we have a great DSL everyone say is soooo fast!” Well, if just life was so easy…

When someone downloads a piece of software from the server, the download is going to travel some public and private roads to get from here to there. For simplicity, let’s call this “the internet”. You download is broken into small pieces, also known as packets, that are sent over the internet from the server to your machine. The speed which they travel depends on many things.

How fast can they leave the server and how many of them can leave at the same time?You see, if your neighborhood one car bridge is clogged in the morning when everybody goes to work, only so many cars will get on the freeway per hour.

How wide are the roads the packets travel on (what is known as bandwidth)? Keep in mind that between here and there, it is going to pass through many roads. Imagine the network equivalent of an LA rush hour traffic and you can imagine your packet cursing while is is stack in traffic very far from your clear street.

How many traffic lights does it have to pass in its way? (on the internet they are called HOPs, which happens when the packet passes through a router). The further you go, the larger this number. To add insult to injury, not all traffic lights are created equal, and some of them might be very busy and you have no way to avoid them! Those are the public exchanges between various networks, so when your packet needs to go between AT&T & UUNET it must go through some busy exchanges.

Enter the world of content distribution networks, or CDN. A CDN is a network of servers, placed around the world. Each server is referred to as an end point. Add to it some private roads to connect between networks, a.k.a peering, and you get a system that is capable of delivering your download faster than you ever imagined possible.

To start, your downloads are saved in multiple locations around the world. When you start a download , the system will route the request to a server which is geographically and network wise closer, shortening the distance, reducing the HOPs you jump through, and minimizing the networks you have to cross. In addition, if a server is down or busy, the next in line will kick in, so you get redundancy and load balancing for the same price.

It is like when you order something online form California and the retailer will ship it from a distribution center close to your house, with a carrier that gets to your door step twice a day with cappuccinos for the family.

So, with all the new business we are experiencing the load on our download servers started to get out of hand. The servers sit on a very fast line and on a very good network, but still, sometimes even that is not enough. So we switched to use a content delivery network, with multiple end points around the world.

The old download links still work, but the new once are so much faster. Use them.